Multiple lymphomatous polyposis of the gastrointestinal tract: prospective clinicopathologic study of 31 cases. Groupe D'étude des Lymphomes Digestifs.

Background & Aims: Multiple lymphomatous polyposis (MLP) is an uncommon type of gastrointestinal lymphoma. The aim of this study was to analyze the clinicopathologic features and outcome of a large series of patients.

Methods: From 1984 to 1995, 31 patients were enrolled prospectively. Exhaustive staging and immunohistochemical analysis were performed. The first 10 patients were treated with cyclophosphamide-vincristine-prednisolone (COP) and the subsequent 21 with doxorubicin-teniposide-cyclophosphamide-prednisolone (AVmCP). Eleven patients were treated with high-dose radiochemotherapy and stem cell autotransplantation because of partial response or relapse.

Results: Advanced age and multiple polyps involving several gastrointestinal segments characterized initial clinical presentation. The typical tumor cell phenotype (pan-B+, CD5+, and CD10-) along with Bcl-1 rearrangement indicated that MLP is the gastrointestinal counterpart of mantle cell lymphoma. After COP treatment, only 3 patients achieved partial remissions, whereas 80% of patients after AVmCP treatment achieved complete or good partial remission. High-dose radiochemotherapy changed partial into complete remission in 80% of cases. None of the initial 10 patients survived for 3 years, but the expected 5-year survival rate was 59% in patients receiving the anthracycline-containing regimen (P < 0.0001).

Conclusions: MLP is a distinct entity among gastrointestinal lymphomas. An anthracycline-containing multidrug regimen and high-dose radiochemotherapy supported by autotransplantation seem to improve its poor prognosis.